Thamanat Prompow is qualified to be a member of parliament and a cabinet member regardless of his being sentenced to four years in prison in Australia in 1994, the Constitutional Court ruled on Wednesday.
The court's ruling was in response to a petition forwarded by House Speaker Chuan Leekpai, as requested by 51 MPs of the Move Forward Party.
Mr Thamanat, a former army captain, is a Palang Pracharath Party MP for Phayao and Deputy Agriculture and Cooperatives Minister.
The opposition MPs in May last year filed a petition with Mr Chuan, seeking a Constitutional Court ruling on Mr Thamanat's eligibility to sit as an MP and to hold a cabinet portfolio as he was sentenced to four years in prison in March 1994 by an Australian court in a heroin smuggling case.
They wanted the charter court to rule whether Mr Thamanat should be disqualified as an MP under Sections 98 and 101 and a cabinet member under Sections 98, 160 and 170 of the constitution because of the jail sentence.
The Constitution Court ruled that a jail sentence which could lead to Mr Thamanat's being disqualified as an MP and a cabinet member under the constitution must be made by a court in Thailand, not a foreign court.
The sentence handed down by a New South Wales court in Australia had no legal binding in Thailand.
Therefore, Mr Thamanat is still qualified to be an MP and a cabinet member under the Thai constitution, the court ruled.